Stoker



July 14, 1925.

W. MCCLAVE STOKER Filed July 24, 1919 '7 Sheets-Sheet' 1 July 14, 1925.

w. McCLAVE STGKER med July V24. 1919.

'7 sheetsheet s wuwoo -July 14, 1925. l 1,545,783

w. MCCLAVE v sToKER Filed July 24, 1919- n 7 sheets-sheet' 4 July 14, A1925. l

. w. MccLAvE sToxEn Filed July V24, 1919 I m .m m. A

iban

annular July 14, 1925.

W. MCCLAVE sToxEn Filed July 24, 1919 "luft-muws July 14, 1925 1,545,183

. f W. MCCLAVE STOKER v F1185 July 24, 1919 7 sneets-vsneet 1 l 'E6 Bf/8 rea fa a v ra@ l 748 4 1 vwwtoz Wmme t i Patented July 14, 1925.

i. f UNI'iiian'sra.;'Las PATENT critic1.=;'i.ffglf Cil wrLmAMMecLAvn, or sonAN'roN, PENNSYLVANIA; AssIGNoR To. McoIgAvE-Bnopoxs COMPANY,` or soaANroN,rENNsYLvAN1A, aGoRPonATIoN or PENNSYLVANIA. Y

i .,s'roKER.

' Appueation meanuy 24, 1919. seran No. 312,969;

To all whom t may concern:

Be it known that I, VILLIAM McCLAvE, a citizen of the United States, residing at Scranton, in the county of Lackawanna and State of Pennsylvania, have invented certain new andV useful Improvements in Stokers; and I do hereby declare the following to bea full, clear, andeXact description of the same, reference being had to'the accompanying drawings, forming part of this specification.

This invention relates to furnace vconstruction and particularly the mechanism .for delivering coal from` the hopper to the bed and for forcing the delivered coal down the inclined fuel bed vatproper intervals during combustion, finally arriving as .ash Vat the dump grate locatechas is customary, atthe lowers-nd of the grate. The principal `ob ject ofthis invention is to improve themechanism of the various steps of movingthe coal invits travelfrom the hopper to the ashpit, and this object is attained by' various improvements which co-opfe`rate together to secure the desired result. lOne of the novel features of suchimprovement is the 'provision of stationaryand movabley grate bars 4placed alternately inthe combustion chamber, these movable Vand stationary bars being of the well known step grat-e type save that they have sectional tops with integral flattened shanks received in socketed bars, each'alternate bar being pivoted and each of the sectional tops being rabbeted on each side, in order to provide not only for the Aexpansion of the metal due to heat,`but also the gradual growth of the metal, these two conditions together causing the usual warping and deformation "of grate structures, which is practically Vobviated-.by the present construction.' A second feature is the provision Yof means whereby each movable grate bar may be tilted on its pivot to the desired degree while-f other movable grate bars are moved to a greater degree or a .less degree; or may even be stationary, while Vanother 'bar is being tilte'd, thus providing for a graduated movement ofthe Vgrate-"bars at will with the possibility of making the movement of all of the fmovable gratebars simultaneous, and of equal def gree, the latter providing for the even shift* of the fuel down the bedtowards the Vstripped of all dump grate. Athird element of novelty disclosed in the present application is inthe provision of means for moving the pusher bars, lsuch mechanism being carriedon a central shaft, which, in turn, forms the fulcrum or pivot forthe mechanism whichtilts the movable grate bars. I

The tops of each of the grate bars arey so constructed as to provide against warping due to expansion and growth and .also to provide for a non-sifting bed, this ll being taken care of: in part by pivoting alongitudinal follower bar to each stationary grate bar and having this follower bar so pivoted that by the force of gravity it is held in contact with ythe movable grate bar, thus preventing at rall times thesiftingofv thefuel through the grate, and yet possessing all of the advantageous features of an openwork grate. Aside from these fourjh main features, other objects of invention will/'loel disclosed by the detailed description fol.-

.lowing In thedrawings, f p ,i

Figure l represents a vertical section through the grate of a furnace.illustrating in elevation `the mechanism "by which the pushers and grate bars are operated.

Fig. 2 is a front elevation of a small twoe unit furnace embodying my invention.l

Fig. 3 is an elevation of the large beam of the carrierbar, such beam being shown parts for clearness of illustration. Y Fig. t is `a partial elevation of one of the carrier bars in its assembled form, showing the sectional slotted tops in cross section. kFig. 5 is a top plan view of two of the tops. l i fFig. 6 is asectionon line 6 6 of Fig. 4. Fig.` 7 is a section on line 7 7, Fig. 4t. l e Fig. 8 is a section on line 8 8, Fig. 4. Fig. 9 is a section on line 9 9, Fig. 4f.

Fig. 10 is a plan view of one of the sectional topsfitting over one of the journals, illustrating particularly the extended lugs whereby this section is held down on ythe trunnion of the movable element. p

K Fig. 1l is an end elevation of] one of the topsnext to the dump grate.

y Fig. 12`is a side elevation of the partsof the carrier` bar in 'proximity to the journal for the dump gratev section.

i of the carrier bar top nearest the furnace front.

Fig. 14 is an elevation at right angles thereto.

Fig. 15 is a partial section of thecentral portion of thefgrate as lshown injFig. 1, but on allarger -scale,land illustrates one of the movable grate bars in elevated position,

to showv the relation of the follower bar in' closing the gap between rthe proximate sections.

Fig. 16 is ,an elevation of the lmovable lgratebars looking toward .the front .of the farmacov Fig. 17 a section on line 1717 of Fig.

"Fig 18 5isan :elevation of the movable slotted grate bar with .the tops removed.

Fig. x1791's a vertical central -section ,of the Fio. 20 is a view similar to 16, .butof ne :Stationary .grae ,bzw-

Fig 21'is a section on 15. l l Fig. 22 is an ,elevation of the stationary slotted grate bar with the .tops removed.

23 is Ya vertical section through the oenterftherooi i l 24 is an .elevation `o-f the follower bol# 25 is a vert the same.

Fig. 26 is a section ,on line V26-26 of line 21-21 of ical sectional elevation 7of Referring now to Fig. 1, the furnace of the step grate type havingtheusual rear Well 29, oppor .masonry 30; ashpit 31 and metal furnace front 32, supported by an beam 33 embedded in the usual frontpier or Wall 34. Extending from lthe front 321th@ the rear wall 29 are placed the carrier bars 3,5

bolted to the front' wall through holes 3 6 yand having hooks 37 engagingin ainetal reinforcement 38 in the rear wall. Arranged between these carrier bars and longitudinally of the furnace 1are a series of vmovable grate bars- 41 and 42 above each of which is a single follower bar piyoted as at to the stationary grate bars 45, one of these-sta' tionary bars being above the'tOpI-mostmovable bar 40 and Vanother stationary grate bar `anditsY accompanying follower bai` 43 being located below the lowermost movable grate bar 42, Athe lower follower bar cooperating with the smooth rounded surface lof 'the dump grate 47, thelatterbeing of .the 'Hotel oolslnotoo Aand forming 11o Per# ticular part of the presrait invention, ,save in Acombination withthe ,novel.feattires` The Supply of ooals led from the' hopper defined between the rear plate 51 and the @lamine hopper front 52- vTho oool posses through the' narrow' mouth .53, .east ,ont-off 'gate`54, and falls the plate y5 5'of the vfrom the furnace front 32, provides -a pivot for the sleeve/ 58 to Vwhich are rigidly at- VLtache'd"arms 59 which' are preferably integral with -the sleeve, these arms being con- Enected with the rods 60, 61, 62, which opcrate the movable grate bars 40, 41 and 42, respectively, movement being imparted to the grate bars by turning the sleeve 58 on the shaft 561/2 by y,means .of lthe kusual steel Ahand lever (not shown) which :is inserted in the ysocket in the boss6g3 in the center of the ,sleeve 58. To one side of each furnace unit is a small bracket pivotally carrying an angle arm 1(having a connection 467 at lits .lower end to a link ypgivotedto the offset arms :69 Eof the dump grate, yso .that ,by inserting the roper hand leverin the ,socket of rthe ,bossPZO the .angle arm 66 may bemove'd about its pivot, this in turn moving .the `dump Aesorto f4.7 about :its pivot 71 and Polfloittiog the burned out coalnr ash to drop into the .pit 31, yin the usual way.

' The .general operation of Vthe `furnace has now been described and .the l,details of .the

various parts as yi,llusztrated ,in-the remaining .figures will beexplained;`

Referring now'to Fig. 3, illustrating the carrier ibar 135, this ,bar .as .before statedex- ,tends from the vconnection 36. at the front end ,of 4the furnace ,to the v.rear wagll 38 and furnishes the support for all of .the g1g-'ate ,bars k,and also the dump grate, The bar lis ytherefore built in ,truss style with thickened ,top and bottom flanges, as shown in a numlber .of the small sectional views, and has a relatively thin .central web 72 reinforced at regular intervals by the stilfening ribs 73, lthere being a rib Lequisiaced on either side of each ,of the bearings i4, these bearings affording' support for the trunnions 75 of .the movable grate bars. Between each .pair ,of trunnions 75 is :a raised projection 76 havino sloping sides so as .to firmly seat the sectiona loi] lll)

lair ,openings 79 terminatingat the upper section or face in narrow elongated slots 80, preferably 6 number, ,as shown in Fig. 5. "The sides of these ,caps taper very slightly inwardly from the face l81 to the bottom .edge 82'k at which point anair inlet 83 is formed since the edge 8 2 is not only apaced away from the metal of the bar but islooo topolod `Sloorpli inwardly to. provide.'

vthe web such air space. At their four lower corners the sectional caps 7 7 arelprovided with feet 84 which seat in recesses inthe bar 35 and this engagement is made secure by the bolt 87 embedded in the central portion co `of the cap 77 and extending through a greater in diameter than the thickness of thel web. It will also be noted from-this ligure that the nut 91 which is preferablyof non-corrodible metal engages a .flat surface 92 at the bottoni of a thickened portion of the bar 35 and also that thethickened portionof the bar'35 is generally V-shape-dat its topportion to assist in the formationof air inlets from leither side of lthe carrier bar.v This air7 under pressure or otherwise, passes between the bar and the .side flanges 93 ofthe sectional caps and passes through the tapered air openings 79 to the slots in the face of the caps, and invso passing cools the metal and prevents the carrier bar itself from being warped and at` the same time supplies the air which is necessary in the coinbustioniofthe fuelg` i The sectional caps 78 are somewhat similar tothe caps 77 see ligs.V 4 to 9) but have only two slots 80 on either side of the central portion 95 wliichforms the cap-plate of the bearings `74. At eitherend of the cap 78 is an extended lug 96corresponding inv height and shape t0, .the projections-76 extending upwardly fromV the ba-r-` 35, these lugs beingl held down against the beam :bv

means of their connection with thebolted caps 77 which overlap these lugs `936 on either side of the top 7,8. i

The bolted cap section showninvFigs. -13

and 14 is `similar to the caps 77 but is cut away at one corner as shown at 97 to form thefront surface of the grat-e structure, this surface of the cut away corner being atan angle of preferably 35 to the top line of the grate and carrier bar `caps softhat said surface will be horizontally vdisposed when ythe `sections are assembled in the grate structure. v

Each of the movable grate bars consists of a slotted bar 100 each side of which has reinforcing ribs 101 and 102 at the'top and bottom bounding the thinner web 103 so that each side of the `grate bar shows in' cross-section a structure somewhat like an:

I-beam thus forming an internal chamberI 104 which is bounded at either end of the grate barby the plate 106 which carries the trunnion 7 5 forming the pivot on which this slotted grate bar turns. yBetween theseV end plates 106` are located a number of lugs 107 corresponding infnumber to the;

number of movable gratebars in each vertical set, henceyin the present showing,

three, each beingvpierced as at 108 to receive the angle connection 109v which isy tapped to receivel the threaded endof the appropriate connecting rod Awhich is then locked in position by a lock nut 110,. the location of the movable grate bar with vrespect to the front of the furnace determining which of the pierced lugs 107 is to yreceive the angle member 109, each of the grate bars, however, being identical in construction. y c* Y Y Referring now to Fig. 1157 the upper pro- Y tection for each movable gratel bar is shown to consist of a plurality ofhollow tops each having a rounded front wall 111 and an integral elongate-d shank 112 Which'passes through the chamber`104 topractically the lower limit of the flange 102 at the lower end of the slotted bar. Preferably, one or more small lugs 113 vof relatively soft metal are embedded in the lower tip ofthe shank 112V and wlienthe top is in proper position f inuthe slotted bar these lugs are bent forwardly, as shown in Fig.y 15 so astoclincli the top in place. Thesetops have side walls or fianges114 and attheir rear facesshow a plurality of partitions-115, 116 andl117 spaced apart so as to form air openings 1118 .communicating with the front and-*lower sides ofthesetops7 thuspermitting a constant supply of air to the vfuel bed.`

Referring now to Fig. 1?, particular attention is called to the rabbeting between the adjacent sectional tops, Thisioint ing made by each .alternate top having Van extended shelf 120 on either `side overlapping but not touching aco-operating shelf 121 .on the adjacent top except for the small integral lugsk or spacing blocks 122 which larepositioned relatively far apart on either the shelf 120 or preferably'on-the shelf 121, as shown. This iabbet joint prevents sifting of the fuel through the grate and yet allows material expansion of the tops themselves and the length of the shelves `and their oveii'hangis such as to take care of the gradual growth of the metal as well the expaiisionidue to the heat of the furnace; The stepped horizontal vpartitions of the tops also prevent sifting of "the fuel since these partitions lie in horizontal position in the normal operation of the. grate and at the time the movable bai's are tilted to force the fuel downwardly on the gratetlie spaces bef1 tween the partitions are atsiicli an angle l rear edge123iof the movable grate bar top.

l. il)

' ln this top there are but two'air open-ings A rier bar and threadedto receive a 128 located` between the central partition r129 and the upper wal-l 124 and the lower-wall 1136', respectively. Y

The slotted bar for the stationary grate section is quiteV similar in central cross section to the similar part of the movable grate bar, but the former is provided with end plates 131 which are bifurca'ted at their lower ends toI provide mouths 132 which straddle small lugs 133V integral with the carrier bar 35 forming the malin support for these bars. At its upper `and forward end each end plate 131 is provided with an an'- guiar lug 134 having a central hole 1235 to receive a bolt 136 erfi'tending from the carnut 137 to hold the stationary grate bar in fixed position. By `removing thesey twofbolts 136 i from the ends -'of-the stationary grate bar,

this bar may be vthen liftt-rdk right out of place from off the lugsj133,tal ing with it,`

of course, the follower bar 48 which is pivoted at 140 to the rearwardly extending lugs 141, positioned one on eithersideof the cen# ter of thestati'onary slotted grate bar.

The follower bar 43 consists` of a vertical plate 142 and an integral slotted membei143 at right angles thereto and therefore` horizontal and having at its rear edge a downturned portion 144 normally resting against the curved wall 111 of the movable grate bar top or in the lowermost follower bar 43 against thesimilar curved wall of the dump grate. The horizontal wall or shelf 143 of the follower bar is deeply slotted asy at 145 at regular intervals throughout its length to provide for the proper passage of airA and the necessary expansion and contraction, while minimizing the tendency to! sifting and warping. Each of the fingers 146 formed by the slots 145 is centrally stiflened at its lower section by an angular bracket rib 147 providing the necessary strength, and at the front end of each follower bar there is a pair of pierced ears 148 located adjacent to the lugs 141 of the slotted bar and forming withthem the pivotal con y nection whereby the follower bar is permitted to fall by gravity against the rounded face of the next lower element, thereby sealing the same against sifting of fuel and yet permitting free movement of such lower element as well as the necessary expansion and contraction of both members.

Referring now to Figs. 1 and 2 the sleeve 58 is loosely mounted on the shaft 561/5v supported from the furnace front B2 by the .brackets 571/?J and is held against'l'ongitudinal movement thereon by the enlarged hfubs 150 of the arms 151 which are keyedv to the shaft 561/2 and are held in place longitudinally of the shaft, not onlyr by Vsuch keys' but also by their being positionedbet'ween the pedestals y571/2 and thea sleeve 58. On

'arms' 59 that is each sleeve '58 are "three integral' arms 59, 59h' and 59C, which are received inthe bifurcated heads: 15:3* ofthe angle lpieces :1'54 which are" tapped attheir rear ends tov re? ce'ive the threaded connecting rods 60', 61 or 62, as the case may be.

Preferably, the arm- 59a nearestv the'V center of the :furnace in a twolunit type is connected to the nearest 'movable grate bar section,` thus being attached to connecting rod 60, while the central arm y59b will be con.- nected to rod 61, thereby operating the centralmovable grate bar section, and the remaining arm 59C fwill be connected to the connecting rodk '62j nearest the dump grate.k Each ofk thebifurcated heads of the angle pieces, 154 is provided with three l holes which vwe will number 1, 2 randB, in accordance with their distance fromthe front of the'furnace and-we'have denoted the arms as-59`159b and 59c in accordance with their distances fromthe center of they furnace. The pins 156, when not in use forconnect# ing 'the head and 'arm through one of the threeholes mentioned, are left in the little receivingbracket `Orholder 157 attached to the' furnace front,'ju'st at the pointl where thevfront is indented sharply, yforming la right angular recess .having` an' upperv wall -158and a rear or lower wall 1591/4); K ,n

Now, when one'of the pins 15,6I iswinf serted in hole No. 1 of arm 59a, another pin in hole No. 1 ofarm 59" and the'third.. pin in hole No.v 1 o'farm 59C, and the metal lever bar isinserted in thes'ocketfof the project:

ing-boss 631' atl lthe 'centerof the sleeve 58V that movesf'theba-rs on the right hand side of the furnace 'and' this lever is pulled downwardly" so that the'sleeve will revolve until the stops 159 at thev lower portionsof thev movable grate bars` strike against the lugsk 160 extending from the carrier bar,

and the action is reversed with the lever bar'l until the lugs on the grate bars yare* stopped, a complete full movement of all of the movable bars lwill be made during this action. Bearv in mind, however, that theV pusherarms y151 have not revolved in the foregoing action as they have been held by a hooked stop 161 pivoted at 162to a small ear 163y on the furnace front'and. prevented from making any vmotion whatever for these pusher arms 151 are keyed to the shaft 561/53 and do not' revolve inthe action described, it being Vonly the sleeve 58 with `its rigid rota-ted on the shaft 561/2v as a pivot., ff. a c

` Now, let fus change the arrangement of the pins, i. e., put a.' pin in arm 59a, 'hole 1, another in arm 59",l hole 2", and athirdY pin in arm' 59, hole 3', then, using the. metal lever as before, 'we' have a differential movei ment', the resultbeing lthat the greatest movement ison the shortest rod, andthe shortest' movement 'is' on the v longest rod:

lll)

Now, let us again place the pins differently, i.e., insert pin in arm 59C, hole 1, another in arm 59h, hole 2, and another in arm 59a, hole 3. Then, by using the lever as before, we have the differential movement looking the other way, that is, the greatest movement at the rear end of the grate and the` least movement at the front end of the grate. Again, should it be desired to give movement to only one of the movable bars, then the bar desired should be connected by placing a pin in the appropriate hole to produce the throw desired and the other two pins may be removed altogether, placing them in the holder 157 provided for that purposeand proceeding as before. It is needless to add that if two bars are to be moved instead of one it is merely necessary to place the two pins in the appropriate connections and remove the other pin altogether and proceed as before. The selective movement of the grate is one of the prin- 'cipal features of this invention, attention being particularly directed to the fact that only the alternate grate bars are moved, half of the grate bars being stationary, except for the slight pivoting of the relatively small follower bar Z13 at the lower rear edge of each stationary bar. The two pusher arms 151 are as previously mentioned keyed to the shaft 561%?J and each is bifurcated at its upper end 164 to receive a link 165 pivoted as at 1661/2 to the pusher bar 57.

While, for convenience of illustration the door 166 is shown resting against the sealing rib 167, this is the normal position only at night when the gate 54 is in closed position, i. e., at its upper limit of movement, and during the day, or rather the time the furnace is in operation, under full charge, the door 166 is raised by means of its handle 168 and held in elevated position by inserting a pin 169 in hole 170.

Under normal circumstances it is the intention to operate a furnace of the size illustrated entirely by hand, inserting the metal lever bar in the appropriate sockets to rock either the shaft 561/2, the sleeve 58, or the dump grate section 47, and, for a small size furnace it will be found comparatively easy to operate both of the pusher bars together, and for such purpose as well as to connect` up adjacent pusher' bar sections for power operation, I provide an extended bracket 171, extending towards the adjacent section of the furnace from each arm 151 and I provide a sliding pin or bolt 172 loosely mounted in cored openings in each side of one bracket 171, so that this pin may be moved by means of its handle 173 so as to connect up adjacent brackets 171 or may be withdrawn entirely within the bracket 171 in which it is mounted, thus making the connection and disconnection of the pusher bar sect-ions an extremely simple matter. In so operating by power, I preferably make use of a small crank arm 1711- connected to a similar crank 175 on the power shaft176 by means of a link 177 in an ordinary manner, preferably having the crank 175 at either the central portion of the furnace or at one side thereof and having but the one link 177 as will be understood. l Y

To prevent passage of Vair through the slots formed for the reception of the connecting bars I mount a plate 180 on each connecting bar tightly fitting the same and permit this plate to slide on the wall 1591/2 in a pocket formed by a cover 181, thus reducing leakage amount.

What is claimed is:

1. In a. stoker structure, a plurality of rocking grate bars, a boiler front having an indented portion provided with a plurality of slots, brackets on said front, a shaftV mounted in said brackets, arms on said shaft, rods passing thru said slots and pivotally and adjustably connecting said arms and said grate bars, and a slide closely fitting each rod and resting against said indented portion to close the exposed port-ions of said slots, each of said slides lying substantially normal to the axes of said rods.

2. In a grate structure, a plurality of rocking grate bars, a rod adjustably connected to each bar, a head secured to each rod, a rocking shaft, a plurality of arms movable with said shaft and in proximity to said heads, and means for securing a head to its arm in any one of a plurality lof points, whereby the angle of rocking of one grate bar may be varied without affecting the angle of rocking of the remaining grate bars.

3. In a stoker structure, a main shaft, a pusher, connections between said pusher and said shaft, a plurality of rocking grate bars, a sleeve loosely mounted on said main shaft, and means detachably and adjustably connecting each of said rocking grate bars with said sleeve.

4. In a non-shifting grate structure, a grate bar consisting of a plurality of end members each having a forked bottom and a perforated laterally extending lug, a plurality of web members connecting said end members and spaced apart to form a slot to receive the Shanks of sectional grate bar tops, and a plurality of lugs extending from one of said webs to form a support for a pivotally mounted follower bar.

5. In a non-shifting grat-e,a plurality of carrier bars each having a plurality of inwardly extending lugs, a plurality of stationary grate bars resting on said lugs and secured to said carrier bars by means of bolts, lateral extensions from each of said stationary grate bars, a follower bar pivotalto an inconsequential llO ly mounted in the entensions of each of said stationary grate bars, and a rocking grate bar pivotally Inonntecl between said carrier bars between each stationary grate bar and tlie follower bar of the adjacent stationary bar.

6. A top for a grate bar Consistingof three parallel horizontal shelves side flanges connesting said shelves and a flattened triangai: lar shank integral with the central horizontal shelf, and ineans Carried by said shank for securing said topfto a grate bar.

7. A rocking giiate bar element including plurality of end pieces, a trunnion on each of saicl end pieces for pivot-ally mounting the grate bar, a plurality of parallel spaced Webs connecting end pieces and proy vdmg a Slot for .the ,reception of grate bar tops, L plurality Of grate bal' tops having their Shanks Within said slot .each having.

e plurality Qi' horizental .shelves above the axis of said -trlmnions and having an ntegral shank below the axis of said trnnf n-,ions when in ordinary position, a pluralityy of side flanges lon each grate (top connecting said shelves and an arenate Wall Connecting the extren'iiti/es ko said side flanges, and' Vmeans pivoted to the lower end of one of WILLIAM MCGLAVE. 

